From: Jean Privat <jean@pryen.org>
Date: Tue, 9 Aug 2016 00:44:00 +0000 (-0400)
Subject: rta: fast fix to avoid resolving illegal types.
X-Git-Url: http://nitlanguage.org

rta: fast fix to avoid resolving illegal types.

This requires a more in-depth work to improve the model.
Another improvement can also to teach RTA the context of object mechanism
so that only legal receivers are attempted.

Signed-off-by: Jean Privat <jean@pryen.org>
---

diff --git a/src/rapid_type_analysis.nit b/src/rapid_type_analysis.nit
index 88e2b7e..c5ddc4a 100644
--- a/src/rapid_type_analysis.nit
+++ b/src/rapid_type_analysis.nit
@@ -313,6 +313,7 @@ class RapidTypeAnalysis
 				if not ot.can_resolve_for(t, t, mainmodule) then continue
 				var rt = ot.anchor_to(mainmodule, t)
 				if live_types.has(rt) then continue
+				if not is_valid_type(rt) then continue
 				if not check_depth(rt) then continue
 				#print "{ot}/{t} -> {rt}"
 				live_types.add(rt)
@@ -329,6 +330,7 @@ class RapidTypeAnalysis
 			for t in live_types do
 				if not ot.can_resolve_for(t, t, mainmodule) then continue
 				var rt = ot.anchor_to(mainmodule, t)
+				if not is_valid_type(rt) then continue
 				live_cast_types.add(rt)
 				#print "  {ot}/{t} -> {rt}"
 			end
@@ -336,6 +338,16 @@ class RapidTypeAnalysis
 		#print "cast MType {live_cast_types.length}: {live_cast_types.join(", ")}"
 	end
 
+	# Quick and dirty check that a forced type resolution gives a legal type
+	# TODO: move up in the model and kill `can_resolve_for`
+	private fun is_valid_type(mtype: MType): Bool
+	do
+		if mtype isa MGenericType then
+			return mtype.is_subtype(mainmodule, null, mtype.mclass.intro.bound_mtype)
+		end
+		return true
+	end
+
 	private fun check_depth(mtype: MClassType): Bool
 	do
 		var d = mtype.length